The US coast guard is deploying drones to catch increasingly tech-savvy drug traffickers

At any time, the US coast guard has just three to five cutters, or large manned vessels, assigned to patrol about 6 million sq miles of sea spanning the Caribbean and the Gulf of Mexico to the eastern Pacific Ocean, through which most of the cocaine bound for the US passes.

To tackle the momentous task of monitoring these vast stretches of ocean, this year the coast guard began to use the ScanEagle, a Boeing-manufactured, 10-ft-long drone similar to a model that was used by the US marine corps in Iraq. The drone recently concluded a six-week deployment in the eastern Pacific Ocean with the coast guard cutter Stratton.

The ScanEagle is launched into the skies from a catapult on the flight deck and scans the surrounding waters for targets, the Associated Press reported from aboard the Stratton. The drone takes into account things like a vessel’s size, cargo, and movement, to determine if it might be a security threat. When a “target of interest” is detected, a go-fast boat is launched, and the chase begins.

The coast guard’s efforts to upgrade its technology—previously it added infrared video and now has drones—along with a spike in coca production in Colombia in the last few years means that they have been particularly productive in seizing smuggled narcotics. In 2016 the coast guard set a record by seizing over 240 tons of cocaine valued at $5.9 billion and arresting 585 smugglers.

The tech upgrades have come in response to drug traffickers who have developed new stealth methods, including homemade “narco-submarines“ and drones. In July 2015, a US Navy pilot spotted a 40-ft-long, blue semi-submersible 200 miles off the coast of Mexico leading to the coast guard’s biggest drug bust ever, involving 16,000 pounds of cocaine worth $181 million. And in November 2016, Colombian authorities confiscated an unmanned aerial vehicle that traffickers were using to transport drugs to Panama.